Honda Avancier Smoking: Bad O2 Sensor or Worse?

Hey there! I had a similar issue with my 2001 Honda Accord (and I've also owned an Inspire). I'd say I have some experience working on cars, mostly basic maintenance and troubleshooting. Those symptoms sound exactly like what I dealt with! Lambda/O2 sensor heater failure can definitely cause all those issues, black smoke, rough running, and that annoying fuel consumption increase. I took mine to my regular workshop where they confirmed it with a diagnostic scan. The whole thing, including parts and labor, set me back 375 Euro, but it was totally worth it. Car ran like new afterward! Before I share more details about my experience, could you tell me if you've had any other symptoms? Also, have you scanned for error codes? Would help to know if we're really dealing with the same issue here. Pro tip: Don't wait too long to fix this, running with a bad O2 sensor can cause more expensive problems down the road.

Thanks for sharing your experience! My Avancier has 49651 KM and had its last service about 3 months ago. You might be onto something with the O2 sensor, gonna get those error codes checked tomorrow at a local shop. Just hoping it won't burn a hole in my wallet! The jerking and power loss are really starting to drive me crazy, especially during my daily commute. Did your car also have that slight hesitation when accelerating from a stop?

Hey again! Yeah, I totally remember that hesitation you're talking about, my Accord did exactly the same thing! It was super annoying, especially in traffic. That slight pause and jerk when pressing the gas pedal was making me nervous every time I needed to pull out quickly. Since we last chatted, I actually remembered something that might help you out. Before I got mine fixed, I noticed the symptoms were always worse when the engine was cold, especially in the morning. Was like the car needed a coffee to wake up properly! Did you notice anything similar with yours? With 49651 KM, your Avancier is still pretty young, mine had almost double that when the O2 sensor went bad. But these things can go wrong at any mileage really. The good news is, once I got it fixed, all those symptoms disappeared completely. The car felt like new again, and my fuel consumption went back to normal within a tank or two. Quick heads up though, make sure the shop checks all the O2 sensors. My mechanic initially only checked the pre-cat sensor, but it turned out the post-cat one was the troublemaker. Could've saved some diagnostic time if we'd checked both from the start. Let me know what those error codes say when you get them checked!

Thanks for all that detailed info! Those symptoms you mentioned about it being worse when cold, that's exactly what I'm experiencing! Every morning it's like my Avancier is throwing a mini tantrum until it warms up. You've pretty much convinced me it's the O2 sensor causing all this trouble. Really appreciate the tip about checking both sensors too, definitely going to mention that to the mechanic tomorrow. It's such a relief to hear that fixing the sensor solved all those issues for you. The fuel consumption thing is killing me right now, so knowing it goes back to normal is great news. Will definitely update once I get those error codes checked. Fingers crossed it's just the sensor and nothing more serious! Thanks again for sharing your experience, it's been super helpful!